This project will provide the characterization of the organization and expression of several cistrons in B. subtilis coding for stable RNAs, including ribosomal and transfer RNA. Several recombinant plasmids containing regious coding for 23, 16, 5, and 45 RNAs have been isolated. They are mapped with restriction enzymes and the coding properties of each fragment determined. The direction of transcription will be determined. The presence of a functional promoter site for proper initiation of RNA transcription will be determined by polymerase binding and protection against nuclease digestion and by in vitro transcription studies. The DNA sequence of the insert will be determined. Finally, the possibility of differential expression of different cistrons coding for stable RNAs during different stages of spore development and outgrowth will be assessed. The organization and expression of the rRNA cistrons will be compared to the situation in E. coli. The experiments proposed here will allow determination of the sequence of the stable RNAs in this organism.